Investigating verbal creative problem solving - the role of search as a function of task difficulty

Solving ill-defined problems like the compound remote associates (CRA) can be regarded as a dynamic search process through a problem space. The solution path is unknown and the solution relies on finding remote semantic associations. While this task has been used to study insight, little research has been done on the dynamics of the search process itself: How does search change as a function of restructuring the problem space and which brain areas modulate this process?
To investigate these questions, we developed a modified CRA paradigm using semantic priming to induce restructuring: In contrast to the semantic close prime condition, participants need to reinterpret the first target word in the distant prime condition to derive a solution.
We measured BOLD activity of 30 participants performing the modified CRA task instructing them to indicate every potential solution they think of. While accuracy decreased, response time and the amount of potential solutions increased for the distant prime compared to the close prime condition. The univariate whole brain analysis revealed a stronger activation for the ACC and bilateral Anterior Insula network for the same contrast at the moment of correct problem solution. Furthermore, this network was positively correlated with the semantic distance between prime and solution.
These results suggest that inducing task difficulty through restructuring leads to higher demands in cognitive control modulated through the ACC and Anterior Insula most likely leading search to more distant semantic associations which results in a change from an automatic to a more conscious search for solutions.